Pool Plaster,Epoxy,Xypex,Polyurea.....Which is best to seal your new shotcrete pond?Crazy troweling bottom of pond for a proper smooth surface for sealing Pool Plaster,Epoxy,Xypex,Polyurea.....Which is best to seal your new pond? This has been a question for many for decades. Let's look at a few sealing products...let's start with plaster...